Field of the Invention
The present invention relates to a posture estimating apparatus and a posture estimating method which are suitable for estimating a posture (or a pose) of a multi-joint object, and a storing medium which stores programs for the posture estimating apparatus and method.
Description of the Related Art
As typical methods of estimating a posture of an object in an image, there are a method of obtaining a kind of posture by using a discriminator, and a method (fitting) of comparing an image and a temporary posture with each other and then gradually modifying the temporary posture so as to reduce a difference therebetween. More specifically, as the method of obtaining the kind of posture by using the discriminator, there is a method of determining a whole posture by utilizing one or more local features. Incidentally, Japanese Patent Application Laid-Open No. H10-124677 discloses a method of sequentially selecting each two partial shapes of a target, sorting out posture candidates based on an arrangement relation of the selected partial shapes, and then determining the final posture candidate. Moreover, as a method of obtaining a posture of an object, there may be a method of uniquely determining the posture based on a mutual relation between a plurality of local features included in a certain posture of the target and the relevant posture.
However, the method as described in Japanese Patent Application Laid-Open No. H10-124677 of narrowing the posture candidates by utilizing the arrangement relation of the local features premises that the arrangement relation of the local features is fixed. Consequently, the relevant method can be applied to a rigid body of which the shape has previously been decided but cannot be applied to an object of which the shape is highly changed. In addition, the method of uniquely determining, as the possible posture of the object, the posture from a previously set model or the like is advantageous in the respect that the posture possible as the object can surely be obtained. However, in the relevant method, since the whole posture is uniquely determined in disregard of local portions, consistency of the posture including the local portions is insufficient.
The posture estimating apparatus according to the specification of this application has been completed in consideration of such problems as described above, and aims to be able to estimate a more consistent posture in regard to a multi-joint object.